[aarch64-port-dev ] RFR: Shenandoah import

[Aleksey Shipilev]

On 10/04/2017 01:21 PM, Andrew Haley wrote:
> On 04/10/17 11:23, Aleksey Shipilev wrote:
>> Yes, and I think the suggestions are silently breaking: they expose "n->is_g1_wb_pre_call()" when
>> UseShenandoahGC=false.
> 
> Right, so this is an actual bug.

Yup, it is a dangerous inconsistency -- whether it escalates to the actual bug is unknown, so we may
assume the worst. To recap: "n->is_g1_wb_pre_call()" is added for Shenandoah. That addition used to
be unguarded, now it is guarded. This is what we have after this integration lands:

-          if (!n->is_Store() && n->Opcode() != Op_CastP2X) {
+          if (!n->is_Store() && n->Opcode() != Op_CastP2X &&
+              (!UseShenandoahGC || !n->is_g1_wb_pre_call())) {

This makes upstream does what it used to do before Shenandoah.

-Aleksey